1. Field of the Invention
The present invention relates to soap dispensers for holding and dispensing fluids such as liquid cleaning agents and the like. More specifically the invention is directed to collapsible containers and valves attached thereto which do not admit air as liquid is being dispensed so that, as liquid is pumped out, the container collapses.
2. Background of the Related Art
This invention relates to improved dispensers for dispensing liquids such as detergents and soaps from containers. Many types of liquid soaps and detergents for personal hygiene are supplied in bottles designed to be inserted into dispensers provided with hand actuated pumps. The bottles generally have a cap designed to be removed from the bottle when the latter is inserted into the dispenser or a seal designed to be punctured or torn off when the bottle is positioned in the dispenser. A drawback to this arrangement is that the bottles can leak when removed from the dispenser thereby creating a mess. A more serious problem relates to the actual method of dispensing the liquids from the bottles. Many dispensers of this type are designed so that, as liquid is pumped from the bottle, air back flows into the bottle to replace the displaced liquid. This can lead to degradation and shorted lifetime of the liquid soap due for example to oxidation. In addition, evaporation of the liquid occurs causing thickening of the soap and may result in blockages in the pumping mechanism.
Accordingly, it would be advantageous to provide a dispenser for dispensing liquid soaps and the like having an economical and reusable valve assembly which automatically opens as the bottle engages the pumping mechanism and closes as the bottle is disengaged from the dispenser and which reduces back flow of air into the bottle as liquid is being dispensed from the bottle.